Device for the weld joining of sheet metal strips

Abstract

A device for the laser weld joining of sheet metal strips includes the following elements: a main frame, a laser welding unit including a laser beam generator for welding the sheet metal strips to be joined and a welding head, a clamping jaw unit supported by the frame and used to clamp the sheet metal strips, and a shearing unit for shearing the head and tails of the sheet metal strips to be joined. The shearing unit includes upper blades mounted to a blade holder and lower blades which can move in relation to the upper blades and which are designed to shear a strip, as well as a blade connecting structure fixed to the frame, the above-mentioned welding head being mobile between the blade holder and the lower blades.

The invention claimed is: 
     
       1. A device for laser weld joining of sheet metal strips running in a steelworks of continuous processing, comprising:
 a main frame; 
 a clamping unit carried by said main frame for clamping sheet metal strips, said clamping unit including first and second clamps each configured to clamp a respective sheet metal strip; 
 a shearing unit for shearing heads and tails of sheet metal strips to be joined, said shearing unit including:
 an upper blade holder, first and second upper blades fastened on said upper blade holder in spaced relation with one another; 
 first and second lower blades moving relative to said upper blades and adapted to shear a sheet metal strip; 
 at least one joint structure of said first blades, said joint structure being in fixed relation to said frame; 
 
 a laser welding unit including a generator for a laser beam for welding the sheet metal strips to be joined and including a welding head slidably mounted for moving in a space located between said upper blade holder and said lower blades. 
 
     
     
       2. The device according to  claim 1 , wherein said first blades are movably disposed for movement between said first and second clamps. 
     
     
       3. The device according to  claim 1 , wherein said joint structure comprises two posts in fixed relation to said main frame and a beam extending between said posts, and wherein at least one of said upper blades is supported by said beam. 
     
     
       4. The device according to  claim 3 , wherein said joint structure comprises shearing jacks supported by said beam for moving said first and second upper blades relative to said first and second lower blades. 
     
     
       5. The device according to  claim 1 , wherein said upper blades and said lower blades are mounted for moving in order to adopt a position of penetration of said upper blades and lower blades wherein said first lower and upper blades are a first blade clearance apart and wherein said second lower and upper blades are a second blade clearance apart, and further comprising mechanical operating means adapted to vary said first and second blade clearances under control of an electronic system for blade clearance control. 
     
     
       6. The device according to  claim 5 , wherein said mechanical operating means are configured to move said lower blades relative to one another for varying said first and second blade clearances. 
     
     
       7. The device according to  claim 5 , wherein said electronic system comprises data collection means adapted to gather and collect data specific to the sheet metal strip to shear and adapted to vary said blade clearances automatically in dependence on the data thus collected. 
     
     
       8. The device according to  claim 1 , wherein said laser welding unit comprises a gooseneck-shaped structure mounted for translation relative to said frame and carrying said welding head. 
     
     
       9. The device according to  claim 3 , wherein said laser welding unit comprises a gooseneck-shaped structure mounted for translation relative to said frame and carrying said welding head, and wherein at least one of said posts is formed with a cut-out crossing the post and at least a part of said gooseneck-shaped structure carrying said welding head is disposed inside said cut-out, in order to cross said post and to be able to slide therein. 
     
     
       10. The device according to  claim 8 , wherein said welding head is mounted for sliding relative to said gooseneck-shaped structure through a system of guides. 
     
     
       11. The device according to  claim 1 , wherein said first and second clamps are disposed in spaced relation with one another and said clamping unit comprises mechanical linking means of said clamps to said main frame adapted to move said first and second clamps from one another and relative to said main frame. 
     
     
       12. A method for laser weld joining of sheet metal strips running in a steelworks of continuous processing, which comprises:
 holding a tail of a sheet metal strip to be joined with a first clamp and holding a head of a sheet metal strip to be joined with a second clamp; 
 shearing the head and the tail of the sheet metal strips in a shearing unit having an upper blade holder and first and second lower blades; 
 subsequently moving the sheet metal strips so sheared closer together; and 
 subsequently welding with a laser beam with a welding head moved into a space in the shearing unit between the upper blades holder and the lower blades; and 
 thereby performing the shearing step, the moving step, and the welding step without releasing the clamps. 
 
     
     
       13. The method according to  claim 12 , wherein:
 the shearing step is performed with first and second upper blades fastened to the upper blade holder in spaced relationship and the first and second lower blades moving relative to the upper blades and configured to shear a sheet metal strip; 
 the shearing unit includes at least a joint structure of the first blades, the joint structure being fixed relative to a frame; and 
 the shearing step includes simultaneously bringing closer together the upper blades, carried by the upper blades holder, and the lower blades. 
 
     
     
       14. The method according to  claim 13 , wherein the blades are disposed to be moved between the first and second clamps.